Like every town across the nation, south suburban Crestwood tucks a notice into utility bills each summer reassuring residents their drinking water is safe. Village leaders also trumpet the claim in their monthly newsletter, while boasting they offer the cheapest water rates in Cook County.

But those pronouncements hide a troubling reality: For more than two decades, the 11,000 or so residents in this working-class community unknowingly drank tap water contaminated with toxic chemicals linked to cancer and other health problems, a Tribune investigation found.

In many ways, Crestwood is a Republican success story, a place where taxes are low despite being situated in one of the most urbanized counties in the United States. The village prides itself on having among the lowest municipal taxes in the country. In the shadow of Chicago, it is a tax haven that Grover Norquist could brag about.

How did Crestwood achieve this? Norquist would be proud of the ways in which the village ignored regulators and endangering the health of its citizens for years. The Illinois EPA informed the village in 1986 that its municipal well had been contaminated by dry cleaning solvents, including the highly toxic chemical vinyl chloride. . . . Given this information from the EPA, local officials might have moved to close the well, or to clean it up. That did not happen. . . .

The well wasn't shut off for good until December 2007, after the Illinois Environmental Protection Agency tested the water for the first time in more than 20 years. The agency found not only that the well was still contaminated but that Crestwood had been piping the water, untreated, to residents.

This decision had consequences. Local residents have reported incidences of cancers, including brain tumors and kidney cancers. Now the Illinois Attorney General Lisa Madigan is investigating why this well was used for more than 20 years after regulators brought its dangers to the attention of local officials. . . .